Control apparatus for internalcombustion engines



Oct. 5, 1948. M. E. CHANDLER f 2,450,826 f CON'ifUxL .PPARA'IUSl FOR NT-ERNAL-COMBUS'ION` ENGINES Filed Nov. 16, 1946' y 2 Sheets-Sheet l ap-a--n-n- INVENToR.

AGENT MILTUNEZ'HHMLER BY Y Oct. 5, 194

MQE. CHANDLER CONTROL AllARA'lUS FOR INTERNAL-COMBUSTION ENGINES I Filed Nov. 1e, 1946 2 sheets-sheet 2 als l v INVENTOR. MLTUNEL'HHWLER BY l Patented Oct. 5, 1948 l CONTROL APPARATUS FOR INTERNAL- COMBUSTION ENGINES i Milton E. Chandler, New Britain, Conn., assignor,

by mesne assignments, to Niles-Bement-Pond Company, West Hartford, Conn., a corporation oi' New Jersey Application November 16, 194.6, Serial No.\71v0,295

(ci. 12a-119) l1 Claims.

This invention relates to control apparatus for internal combustion engines, and particularly f to apparatus for controlling the ignition timing, and for coordinating the control of ignition timing with other conditions of engine operation.

The present invention is an improvement on the. invention described and claimed in my co'- pending application, Serial No. 491,442, led June 19, 1943, matured into Patent No. 2,432,283, issued December 9, 1947. Internal combustion engines 'run most eiliciently, in the intermediate ranges of theirrpower output, with a relatively lean fuel-air ratio and with their ignition timing somewhat advanced.y At high power outputs, approaching maximum power output, such a lean fuel-air ratio and advanced ignition timing cause overheating of the It is therefore desirable to provide engine. means for enriching the fuel-air mixture and for retarding the timing from its advanced condition as the engine approaches its maximum power output. Also, at low power outputs, such as are encountered in the idle range, engines will not ,run smoothly or will stall if the lean fuel-air ratio and advanced ignition timing are used. It is therefore desirable to provide some means for enriching the fuel-air ratio and retarding the ignition timing in the low power output range. It sometimes happens that, because of unforeseen lfactors, it is desirable to operate the engine in its intermediate range of engine power output with a rich mixture'and retarded ignition timing. It is therefore also desirable to provide a manual control which may be operated to secure such operation at any time.

My copending application above referred to shows apparatus for simultaneously controlling the ignition timing and the fuel-air ratio of an internal combustion engine in order to secure" such results.

It is an'object of the present'invention to improveiand simplify such aparatus.

Another object is to provide an improved arrangement of the type described, in which a pressure responsive element which controls the ignition timing also controls the fuel-airr ratio.

A further object is' to provide, in a system of the type described, an arrangement whereby a pressure responsive controldevice operates an ignition timing control'from normal to advanced and back to normal positions upon a continuous increase in the controlling condition; and wherein the same pressure responsive element operates a fuel-air ratio controlling valve from rich to lean andvback to rich positions at the same time that it operates the ignition control.

A further object of the invention is to provide improved electrical switch mechanism which is operable from open to closed to open positions upon a continuous unidirectional movement of a controlling member.

A further object is to provide improved valve.

system for an internal combustion engine, em-

bodying the principles of my invention,

Figure 2 illustrates, somewhat diagrammatic ally, suitable ignition timing control apparatus which may be used in the system of Figure l, and

Figure 3 illustrates a modiiled form of ignition timing and fuel-air ratio control apparatus emy25 bodying the principles of my invention, which may be substituted for the corresponding structure of Figure 1.

Referring to the drawing, there is shown a section i0 of a carburetor body, through which an air passage extends from an inlet i2, past a venturi i 4, a throttle. i6, and a fuel Anozzle I8 to outlet 20.

The venturi i4 sets up an air pressure difierential which is a measure of the volumetric rate of flow of air through the venturi. This pressure differential induces an air flow through a secondary air passage which may be traced from a plurality of impact tubes 22 fwhose ends are open to receive the impact o! the entering air, a connecting passage 24, a conduit 26, a chamber 28 in a fuel meter generally indicated at 30, a.A

xed restriction 32, a chamber 34, a conduit 38, past a valve 38 into a chamber 40, and through a conduit 42 to the throat of venturi i4. The valve 38 is positioned by a ilexible bellows 44. The bellows 44 is sealed, and is preferably partly lled with a uid having an appreciable temperature coetilcient of expansion, so that the valve 38 is positioned in accordance with changes in pressure and temperature in the chamber 40. The function of bellows 44 and valve-38 is to vary the pressure drop across that valve to compensate the pressure drop across restriction 32 for variations in air density, so that the pressure drop across restriction 32 will be a true measure vfuel meter 30, a conduit 50,

of the mass air ow turi. This density compensating effect is more completely described in my prior Patent No. 2,393,144, dated January 15, 1946. v

Fuel flows under superatmospheric pressure from a pump or other source (not shown) and passes through a conduit ".6, a valve 48 in the a mixture control unit 52, parallel conduits 54 and 56, a iet or metering restriction system 58, a conduit 60, a pressure regulator 62 and a conduit 64 to the fuel nozzle |8.

The fuel meter 30 includes a flexible diaphragm 66 separating the chambers 28 and 34. Another flexible diaphragm 68 separates chamber 28 from a chamber 10. A third flexible diaphragm 12 separates chamber 34 from a chamber 14. The three diaphragms 68, 66 and 12 are attached at their centers to the stem 16 of valve 48.

The chamber 14 is filled with fuel at the pressure existing at the outlet of valve 48, which is substantially the same as the pressure on the upstream side of jet system. 58. Chamber is connected through a conduit 18 to the conduit 60 on the downstream side of jet system 58.

The mixture control unit 52 includes a disc valve 80, which is movable between a lean position shown in full lines in the drawing, in which fuel may flow out 0f the mixture control unit only through conduit 56, and a rich position, shown in dotted lines in the drawing, in which fuel may ow out" of themixture -control unit through either of the conduits 54 and 56. The valve 80 is also movable to a position wherein it cuts oil` the flow through both conduits 54 and 56, known as the cut-off position. l

Fuel flowingthrough conduit 56 to Jet system 68 passes either through a fixed restriction 82 or thru a restriction 84 controlled by an enrichment valve 86 biased to closed position by a spring 88. Fuel flowing to jet system 68 through conduit 54 passes through a xed restriction 80. Fuel flowing through the restrictions 84 and 90 also passes through a fixed restriction 82.

The pressure regulator 62 includes a flexible diphragm 94 separating a pair of expansible chambers 96 and 98. The diaphragm is attached at its center to a valve 00. A spring |02 biases the valve |00 toward closed position. Chamber 88. receives fuel from conduit 60. Chamber 96 is connected through a conduit |04 to conduit 26 and thence to the impact tube 22.

The structure so far described represents more or less conventional carburetor structure. An ignition timing and fuel-air ratio control unit which embodies the novel elementsof the present invention is illustrated generally at |06 in the drawings. The unit |06 includes a flexible diaphragm |08 separating a pair of expansible chambers |0 and ||2. The diaphragm |08 is biased downwardly by a spring ||4. Attached to the center of diaphragm |08 is the stem ||6 of a valve ||8. The stem ||6 passes through an aperture in the web portion of a valve member having the general shape of an inverted cup. The lower edge of this aperture forms a seat for valve ||8. The valve member |20 is biased downwardly by a spring |22, so that its lateral walls close a series of ports |24 leading into the chamber ||2. The valve member |20 moves in a stationary guide member |26 in which the ports |24 are located.

The diaphragm |08 also carries at its center an abutment member |28 which projects upwardly therefrom and is rounded at its end to provide a rolling surface engagement with an per unit time thru the venother abutment member |30 carried by a diaphragm |32 which seals an opening in the upper wall of chamber ||0. The abutment member |30 is provided at its upper end with a yoke portion which pivotally carries a switch lever |32. The lever |32 carries at its opposite ends a pair of movable switch contacts |34 and |36. These contacts are located on opposite sides of the switch lever |82. Contact |34 co-operates with a stationary contact |38, while contact |86 co-operates with a stationary contact |40. A spring |42 is held in compression between the housing of unit |06 and a guided retainer |44. The spring |42 biases the retainer |44 into engagement wtih switch lever |32, and thereby moves contact |34 into engagement with station)- ary contact |38 and also maintains abutment member |30 in engagement with abutment member |28. v

The switch mechanism just described controls an electrical circuit for energizing an electromagnet |46 which operates ignition timing control means such as that illustrated in Figure 2. This electrical circuit may be traced from the upper terminal of a battery |48, through a conductor |50, contacts |38 and |34, switch lever |32, contacts |36 and |40, a conductor,|52, electromagnet |46, and a conductor |54 to the lower terminal of battery |48.

Chamber ||0 is connected through a conduit |56 to the conduit 54 and chamber ||2 is connected through a conduit |58 to the conduit 66. The chamber at the outlet side of valve .||8 is connected through a conduit |60 to the chamber 8| in jet system 58.

The ignition control mechanism, as illustrated in Figure 2, includes an armature |62 of the electromagnet |46. Armature |62 is connected through a link |64 to one end of a lever |66, pivotally mounted at |68. The opposite end of lever |68 carries a switch nger |10. Finger |10 is movable between a pair of normal timing contacts |12 and |14, and a pair of advanced timing contacts |16 and |18. A spring |80 biases the lever |66 against a stop |82, so that the finger |10 is in engagement with the normal timing contacts |12 and |14.

The two sets of contacts controlled by ringer |10 control selectively two ignition circuits which extend from a battery through a primary ignition coil |82, finger |10, and either a set of normal timing breaker contacts |84 or a set of advanced timing breaker contacts |86, depending upon the position of finger |10. These circuits are completed through the breaker cam |88 and ground connections |90 and |82 to the opposite terminal of the battery.

Operation of Figures 1 and 2 lThe pressure regulator 62 operates to maintain a substantially constant pressure on the downstream side of the iet system 58. The value of this pressure is determined by the force of spring |02. If the pressure in chamber 88 exceeds that determined by the force of spring |62. that pressure, acting upwardly on diaphragm 94. compresses spring |02 further, and opens valve |00 wider until the pressure in chamber 98 is reduced substantially to its previous value. The pressure in chamber 98 is not exactly constant, because of the regulation-introduced by spring |02, since an increasing 'force is required to increasingly compress spring |02 to change the position of valve |00. However, the range of variations in the pressure in chamber 88 may be made small by proper design of diaphragm 64 and spring |02. `Some variation in pressurevin chamber 98 is also introduced by variations in pressure in chamber 88. This is substantially atmospheric pressure. However, the intended function of regulator 82 is not to maintain an exactly constant pressure on the downstream side of the Jet system, but to maintain that pressure within a fairly narrow range of values, which range is substantially. above atmospheric pressure, so as to prevent vaporization of the fuel as it passes through the Jet. Such vaporization the fuel flow.

The fuel meter 30 regulates the pressure on the upstream side of the jet system so as to maintain the fuel pressure diiferential across the jet might otherwise produce inaccurate metering of system proportional to the air 'pressure diiferential which acts downwardly on diaphragm 88. Since the fuel pressure differential is maintained proportional to the air pressure differential, both of the pressure differentials may be considered to be measures of the air flow. For a given metering restriction area open to the flow of fuel through the jet system, the fuel pressure differential is also a measure of the fuel flow. In the jet system 58, such'a variation in the metering restriction area is accomplished in two ways. In the rst place, the enrichment valve opens under the inuence of the fuel pressurey difierential when that diiferentialexceeds a value sufficient to overcome the spring 88. There is thus provided an automatic enrichment of the fuelair mixture at high power outputs.` In the second place, lay-manipulation of valve 80 in the'y mixture control unit 52. the pilot may select either a lean fuel-air mixture, wherein only the restriction 82 is open to the flow of fuel, or a rich fuel-air mixture, wherein the restriction 90 is also open to the flo-w of fuel.

' In addition to the two controls of the fuel-air ratio mentioned above, the unit |06 controls the ow of fuel through the metering restriction |6| in accordance with the fuel pressure differential across the jet system and in accordance with thel position of the manually operatedvalve 80. When the parts are in the positions shown in the drawing, the valve 80 is in its lean position, and the fuel pressure differential is at a low value, such as would be encountered in the'idling range. Under these conditions, fuel may flow from conduit 56, through conduct |58, chamber H2, through the aperture in the center of guide |26, through the aperture in the center of valve member |20, past valve ||8 and through conduit |60 and metering restriction |6| and on to the engine.

The pressurein chamber ||0 is substantially the .same as the pressure on the downstream side of the jet system; since there is nc iiow through restriction 80 and hence no pressure drop through it. With these condi-tions existing.` let it now v'he assumed that the power output of the engine is gradually increased, thereby gradually increasing the fuel pressure differential. The contacts |38 and |40 are separated, so -thatelectromagnet |46 is deenergized, and the ignition timing is normal. As the fuel pressure diierential increases, then it acts upwardly on diaphragm 08, compressing spring ||4. As the diaphragm |08 moves upwardly, a point is reached where valve ||8 engages itstseat on valve member |20. Siziultaneously. the contact |38 engages contact I4 4 Engagement of valve member ||8 with itsl seat cuts off the ow of fuel through restriction |8I,

same time, engagement of contacts |88 and |40 causes energization of the electrom-agnet |48 and thereby advances the ignition timing.

Furthervupward movement of diaphragm |00 cannot take place until the pressure differential increases suiliciently to overcome not only the spring I I4, but also the spring |22 and the spring |42.I The spring |42 and retainer |44 may be placed, if desired, somewhat to the left of the position shown in the drawing, so that a given upward movement of abutment member |80 requires a greater compression of spring |42 when the lever |32 is pivoting about contact |38 than when the lever is pivoting about contact |34.l

There is, therefore. a considerable range'of vaiues of the fuel pressure differential. during which the increasing fuel. pressure differential causes no change in the fuel-air ratio or in the ignition timing. The extent of this range is determined by the relative strength of these springs. This l' is known as the cruising range, and corresponds with the range of power output lover which the engine may operate efficiently with a lean fuela-ir ratio and advances ignition timing.

As the fuel pressure vdifferential continues to increase. it eventually becomes strong enough to overcome springs ||'4, |22 andi 42. It-then moves ,valve member |20 upwardly, opening the ports |24 so that fuel may again iiow through metering restriction |6I. The fuel-air ratio is thereby again increased. At the same time, the continued upward movement of diaphragm |08 causes the switch lever |32 to pivot about the contacts |38 and |40, thereby separating the contacts |34 and |38, and de-energizing 'the electrom'agnet |48, so

.that the ignition timing is returned to its normal condition.

On the decreasing fuel pressure differential, thereserve sequence 4of operation takes place.

It may, therefore. be seen tha-t I have provided a simplified fuel mixture .and'igni'tiontiming control arrangement wherein one diaphragm controls'both the fuel mixture and the ignition timing, and wherein the fuel mixture is made leaner and the timing advanced over an intermediate range of power outputs, while the mixture is made richer and the timing retarded at either end of said intermediate range.

Whenever the manual mixture control valve 80 is moved to its rich position, the pressures in chambers ||0 and ||2 are equalized, and the spring ||4. moves diaphragm |08 and -its associated parts to the positions shown in the drawing. so that the mixture is enriched and the ignition timing is retarded. It is thus possible for the operator to ensure that the mixture and the ignition timing are established at safe values at any point in the entire range of engine power output.

Figure 3 reference characters and will not be further described.

In Figure 3, two diaphragms 202vand 204 are provided to perform the functions performed by the single diaphragm |08 of Figure i. The diaphragm 202 controls the change from the idle range to the intermediate range of power outthereby decreasing the fuel-air. ratio. At the puts. while the diaphragm 204 controls the change from the intermediate range to the high power output range.

The diaphragm 202 separates a pair of expansibie chambers 208 and 208 which are interconnected, respectively; with another pair of chambers 2|0` and2l2, separated by diaphragm 204. The stem 2|4 of a valve 2i0 is attached to the center of diaphragm 202. A spring 2|8 acts on the diaphragm 202 and biases the valve 2|6 toward open position. The diaphragm 202 carries a movable contact 220 which co-operates with a stationary contact 222. A valve 224 is attached to the center of diaphragm 204. A spring 226 acts on diaphragm 204 and biases the valve 224 toward closed position. 'I'he diaphragm 204 carries a movable contact 228, which co-op'erates with a stationary contact 280. The arrangement is such that contacts 228 and 280 engage when valve 224 is closed and contacts 220 and 222 engage when valve 2|6 is closed. Fuel flowing through the valves 2|4 and 224 flows into a common outlet chamber 230 connected to the conduit |60. The circuit for energizing electromagnet |40 may be traced from the upper terminal of battery |48 through a conductor 282, contacts 222 and 220, a conductor 234, contacts 228 and 230, a conductor 286, electromagnet |46, and conductor |84 to the lower terminal of battery |48.

Operation of Figure 3 When the fuel pressure differential is in thel of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of features shown and described or portions thereof, but recognize that various modiflcations are possible within the scope of the invention claimed.

I claim as my invention; 1. Control apparatus for an internal combustlonengine, comprising a conduit for fuel nowing to said engine, `a metering orifice in said conduit, meansfor regulating the pressure difierential across said orice to con-trol the, rate of flow of fuel therethru, valve means connected in parallel with said orifice for controlling the relationship between said fuel pressure differential and said rate of flow, said valve means having an intermediate range of positions in which it is closed and end ranges in which it is open, ignition timing control means having a normal timing DOslton and an advanced timing position, electrical means for operating said ignition timing control means including switch means. said switch means having an intermediate range of position-s in which said switch means operates to cause movement of said ignition timing control means to advanced position and end ranges in which said switch means'operates to cause movement of said ignition timing control means to normal position, and

' operating means for said valve means and said spring 226, and the valve 2|6 is held open by its spring 2li'. At the same ti-me,`the electromag, net circuit is open because of the separation of contacts 220 and 222. 'I'he fuel metering restriction |6| is therefore open to the flow of fuel, and the ignition timing is in it-s normal position, since electromagnet |48 is de-energized.

As the fuel pressure differential increases, the

spring 2|8 is compressed, and the valve 2|$ gradually closes. When it closes, the contacts 220 and 222 engage. The fuel-air ratio is thereby increased bythe cutting ofi.' of the flow through restriction iii. At the same time, the ignition timing is advanced by energization of elcctromagnet |40.

The spring 220 is made somewhat stronger than spring 2|8, ro that after the valve 2li is closed. the fuel pressure differential must increase by a substantial amount before the valve 224 starts to open. There is thus provided a wide range of fuel pressure differentials, and hence of power outputs, during which there is no change in the fuel-air ratio or in the ignition timing. 4When the fuel pressure differential exceeds the value necessary to overcome spring 220. valve 224 opens, and at the same time the contacts 228 and 280,

are separated. 'I'he fuel-air ratio is thereby min increased. since metering restriction |8| is again open to the flow of fuel. and at the same time the ignition timing is returned to normal through the energization of electromagnet |48.

As in the case of Figure l, if the manual mixture control is moved toits rich position, the pressure dfierential acting on the diaphragms 202 and 204 is equalized, so that valve 224 is closed and valve 2li is opened. and contacts 220 and 222 are separated. The fuel flow through metering restriction |8| is thereby again permitted. and the ignition timing is changed to normal by the energization of electromagnet |40.

'I'he terms and expressions which I have employed are used as terms of description and not switch means including a single diaphragm subject to said fuel pressure differential and effective to simultaneously move said valve means and said switch means between their respective end ranges and their respective intermediate ranges.

2. Control apparatus for an internal combustion engine, comprising a conduit for fuel flowing to said engine, a metering orifice ln said conduit, means for regulating the pressure differential across said orifice to control the rate of Vflow of fuel therethru, valve means connected in Darallel with said orifice for controlling the relationship between said fuel pressure differential and said rate of flow, said valve means having an intermediate range of positions in which it is closed and end ranges in which it is open, ignition tming control means having a normal timing position and an advanced timing position, electrical means for operating said ignition timing control means including switch means, said lever means having an intermediate range of positions in which said switch means operates to cause movement of said ignition timing control means to advanced position and end ranges in which said switch means operates to cause movement of said ignition timing control means to normal position, and operating means for said valve means and said switch means including diaphragm means subject to said fuel pressure differential and effective to simultaneously move said valve means and said switch means between their respective end ranges and their respective intermediate ranges.

3. Control apparatus for an internal combustion engine, comprising a conduit for fuel flowing to said engine, a metering orifice in said conduit, means for regulating the pressure differential across said orifice to control the rate of flow of fuel therethru. a pair of valves connected in parallel with said orifice for controlling the relationship between said fuel pressure differential and said rate of flow, a spring biasing one of said valves open with a predetermined force, another spring biasing the other of said valves closed with a greater force, a pair of diaphragms, each sub- -ject to said fuel pressure differential and cach acting on one of said valves in opposition to its associated spring, ignition timing control means vhaving a normal timing position and an advanced timing position, and electrical means for operating said ignition timing control'means including an electrical circuit and a pair of swit-ches connected in series tl1erein,'each said'swltch being associated with one of said diaphragms and movable thereby to vclosed position when the valve asso'- ciated therewith is closed, said electrical means being effective'when bo'th switches are ,closed to cause movement of said igni-tion timing control means to advanced position 'and when either switch is open to cause movement of said control having a normal timing position and an advanced timing position, electrical means for operating said ignition timing control means iii'- cluding switch means, and operating means for said valve means and said switch means including a single diaphragm subject to a pressure differential indicative of engine power output and effective to simultaneously close said valve means and operate said switch means to advanced timing position or to simultaneously open said valve means 'and operate said switch means to normal timing position.

5. Control apparatus for internal combustion engine, comprising a conduit for fuel flowing to said engine, a metering orifice in said conduit, means for regulating the pressure differential across said orifice to control the rate of flow of fuel therethru, ignition timing control means having a normal timing position and an advancedl timing position, electrical means for operating said ignition timing `control means including switch means, said switchmeans having an intermediate range of positions in which said switch means operates to cause movement of said ignition timing control means to advanced position and endvranges in which said switch means operates to cause movement of said ignition timing control means to normal position, and operating means for said switch means including a single diaphragm subject to said fuelpressure.diferen tial and effective to operatesaid switch means to its advanced timing position when said pressure differential is in aL predetermined intermediate range and to its normal timing position when said pressure differential is outside said range.

6. Control apparatus for an internal combustion engine, comprising ignition timing .control means havinga. normal timing position and an advanced timing position, electrical means for op-4 erating said ignition timing control means and effective when energized Ato move said ignition timing control means to its advanced timing position and when de-energized to move said ignition timing control means to its normal timing position. an electrical circuit including said electrical means and a switch in series, a movable operating member for said switch, said switch comprising a switch lever pivoted'near its center on said member, first and second movable contacts, one on each end of said lever, said contacts being located on opposite sides of said lever, first and secondstationary contacts mounted adjacent the opposite sides of said lever and adapted to be engaged respectively by said first and second movable contacts, resilient means engagingi said lever on one side of said pivot and biasing said' lever to carry said rst movable contact into engagement with said first stationary contact, said member being effective upon continuedmovement thereof in 'i one direction to rotate` said lever about said first i contacts as a fulcrum until said second contacts are engaged-and thereafter to rotate said lever about said second contact-s as a fulcrum and against the force of said resilient means to d-isengage said first contacts, said first contacts and said second cont-acts belngconnected in series in said circuit so that said circuit is completed only when said rst contacts are engaged and said second contacts are engaged, and means responsive 'to a controlling condition for moving said member.

7. Control apparatus-for lan internal combustion engine, comprising a conduit for fuel flowing to said engine, a metering orifice in said conduit, means for regulating the pressure differential across said orifice to control the rate of ow of fuel therethru, valve means connected in parallel with said orifice for controlling the relationship between said fuel pressure differential and vsaid rate of flow, said valve means comprising afirst valve member, a first seat for said first valve member, means biasing said first valve member into engagement with said seat, a second seat formed on said first valve member, each said valve v member and seat 'together defining a fiow path parallel tosaid orifice, a movable operating member for said valve means, said operating member being effective upon continued movement therev of in one -direction first to move said second valve member toward said second valve seat and after engagement of said second valve member with said second seat to act thru said second valve memberon said first valve member against said biasing means and move said first valve member away from said first seat, ignition timing control means having a normal timing position and an .advanced timing position, electrical means 'for operating said ignition timing control means and effec-tive when energized to move said ignition timing control means to its advanced timing position and when de-energized to move said ignition timing control means to its normalvtiming position, an electrical circuit including said electrical means and 4a switch in series, a movable operating memberfor said switch, said switch comprising a switch lever pivoted near itscenter on said member, flrst and second movable contacts, one on each end of said lever, said contacts being located on' opposite sides of said lever, first and sec- 4ond stationary contacts mounted adjacent the opposite sides of said lever and adapted to be engaged respectively by said first and second movable contacts, resilient means engaging said lever on one side of said pivot and biasing said lever to carry said` first movable contact into engagement withsaid first stationary contact, said member being effective upon con'tinued movement thereof in one direction to rotate said lever 'about said first :conta-cts as a fulcrum until said second contacts are engaged and thereafter 'to ro'tate said lever about said second contacts as a fulcrum and again-st the force of said resilient means to disengage said first contacts, said first contacts and said second contacts being connected in series in said circuit so that said circuit'is completed only when said flrst contacts are engaged and said second contacts are engaged, and means responsive means for regulating 'the 11 to a controlling condition for moving both said members, said members beingso positioned with respect to each other and saidtcondition responsive means that said second valve member en- Gagessaid second seat simultaneously with engagement of said second contacts.

8. Control apparatus for an internal combustion engine, comprising a conduit for fuel flowing to said engine, a metering orifice in said conduit, pressure diiferential across said orifice to control the rate of flow of fuel therethru, valve means connected in parallel with said orifice for controlling the relationship between said fuel pressure. rate of flow. said valve means comprising a first valve member, a first seat for said first valve member, means bi-asing said flrst .valve member into engagement with said seat, a second seat formed on said firs-t valve member, each said valve member and seat together defining a fiow path parallel to said orifice, a movable oper-ating member for said valve means, said operating member being eective upon continued movement thereof in one direction first to move said second valve member toward said second valve seat and after engagement of said second valve member with said second seat to act thru said second valve member on said first valve member against said biasing means and move said flrst valve member awaYfrom said first seat, and means responsive to a controlling condition for moving said operating member.

9. Control apparatus for an internal combustion engine, comprising ignition timing control means having a normal timing position and an advanced timing posi-tion, electrical means for operating said ignition timing control means and effective when energized to move said ignition timing control means to its advanced timing position and 4when de-energized to move said ignition timing control means to its normal timing posi-l tion, an electrical circuit including said electrical meaxisvand a switch in ser-ies, a movable operating member for said switch, said switch comprising a switch lever pivoted near its center on said member, iirst and second movable contacts, one on each end of said lever, said contacts being located on opposite sides of said lever, first and second stationary contacts mounted adjacent the oppoposite sides of said lever and adapted to be engaged respectively by saidiirst and second movable contacts, resilient means engaging said lever on one side of said pivot and biasing said lever to carry said first movable contact intoengagement with said first stationary contact, said member being effective upon continued movement thereof in one direction to rotate said lever about said first contacts as a fulcrum until said second contacts are engaged and thereafter to rotate said lever about said second contacts as a fulcrum and against the force of said resilient means to disenage said first contacts, said first contacts and said second contacts being connected in ser-les in said circuit so that said circuit is completed only when said first contacts are engaged and said second contacts are engaged, means responsive to -a variable controlling condition for producing a variable operating force acting on vsaid member, and spring means opposing said condition responsive means, said condition responsive means being effective as said force increases to close said second contacts when said force reaches a predetermined value, then to hold both sets of contacts engaged until said force increases to a higher value sulcient to overcome both said resilient differential and said means and said spring means, and thereupon to fuel therethru, valve means open said nrst contacts.

10. Control apparatus for an internal combustion engine, comprising a conduit for fuel flowing to -said engine, a metering orince in said conduit, means for regulating the pressure differential across'said orifice to control the rate of flow of connected in parallel with said orifice for controlling the relationship between said fuel pressure differential and said rate of ow, said valve means comprising valve member. a first seat for said first valve member, means biasing said first valve member into engagement with said seat, a second seat formed on said first valve member on the side opposite said biasing means, each said valve member and seat together defining a flow path parallel to said orifice, a movable operating member for said valve means, said operating member being effective upon continued movement thereof in one direction first to move said second valve member tow-ard said second valve seat and after engagement of said second valve member with' said second seat to act thru said second valve member on said first valve member against said biasing means and move said first valve member away from said rst seat, ignition timing control means having a normal timing position and an advanced timing position, electrical means for operating said ignition timing control means and effective when energized to move said ignition timing control means v to its advanced timing position and when de-energized to move said ignition timing control means -to its normal timing position, an electrical circuit including said electrical means and a switch in series, a movable operating member for said switch, said switch comprising a switch lever pivoted near its center on said member, rst and second movable contacts, one on each end of said lever, said contacts being -located on opposite sides of said lever, first and second stationary contacts mounted adjacent the opposite sides of said lever and adapted to be engaged respectively by said first and second movable contacts, resilient means engaging said lever on one side of said pivot and biasing said lever to carry said first movable contact into engagement with said first stationary contact, said member being effective upon continued movement thereof in one direction to rotate said lever about said ilrst contacts as a fulcrum until said second contacts are engaged and thereafter to rotate said lever about said second contacts as a fulcrum and against the force of said resilient means to disengage said first contacts, said first contacts and said second contacts being connected in series in said circuit so that said circuit is completed only when said first contacts are engaged and said second contacts are engaged, meansresponsive to a variable controlling condition for producing a variable operating force acting on both said operating members, said members being so positioned with respect to each other and said condition responsive means that said second valve member engages said second seat simultaneously with engagement of said second contacts, and spring means opposing said condition responsive means. said condition responsive means being effective as said force increases to close said second contacts and to close said second valve member on its seat when said force reaches a predeterminedvalue, then to hold both sets of contacts engaged and both rst and second valve members on their seats until said force increases to a higher value sum'cient to overcome said resilient means, said biasing means and a first' andan@ i said spring means. and thereupon to open said first contacts land move said first valve member oft its seat.

11. Control apparatus for an internal combustion engine, comprising a conduit for fuel flowing to'said engine, a metering oriiice in said conduit,

means for regulating the pressure dierential across said orice -to control the rate of now of fuel therethru, .valve means connected in parallel with said orice for controlling the relationship between said fuel pressure differential and said Vrate of flow, said valve means comprising a first ,f

valve member, a first seat for said first valve member, means biasing said first valve member into 14 l valve member against said biasing means and move said'ilrst valve member away from 'said first seat, means-responsive to a variable controlling condition for producing a variable operating force acting on 4said operating member, and spring meansfopposing said condition' responsive means, said condition responsive me-ans being effective as said force increases to move said second valve member into engagement with said second seat when said force reaches a predetermined value,

- then to hold both rs't and second valve members act thru s-aid second valve member on said first on their seats until said force increases to a higher y value sumcient to overcome said biasing' means and said spring means,and thereupon to move said iirst valve member on its seat.

.` v MILTON E. CHANDLER..

REFERENCES' ciTED The following references are of record in the file of this patent: y UNITED STATES PATENTS Number Name Date 2,378,037 Reggio T---" June 12, 1945 2,390,166 -Parkin's et al. Dec. 4, 194 5 

